Cartography and the Internet:
Implications for Modern Cartography

Michael P. Peterson

University of Nebraska-Omaha
geolib@cwis.unomaha.edu

Abstract

The number of maps that are currently distributed through the Internet is
phenomenal. A single World-Wide-Web site operated by the Xerox Palo Alto
Research Center in California processes over 90,000 Internet requests for
maps every day and the number of web sites that contain maps numbers into
the tens of thousands. A major reason for the increase of map distribution
through the Internet is cost. It is simply less expensive to distribute
color graphics through the web than it is to print and distribute maps on
paper. A second reason is time. Maps on computer networks are delivered
in a fraction of the time that was previously required. A third reason is
the potential for interaction. Users can interactively choose a location
to map and the features to include on the map. The implications of the Internet
for cartography are examined through a World Wide Web home page at http://maps.unomaha.edu/NACIS/paper.html.

Introduction

No longer restricted to paper, maps are now transmitted almost instantly
from place to place. The change in the medium of map distribution has been
phenomenal. By the mid-1990's, a single computer operated by Xerox Parc
Research Facility in California, processed over 90,000 Internet requests
for maps every day. The number of Internet sites that contain maps probably
numbers into the tens of thousands. Many of these maps, such as those depicting
weather patterns, are updated continuously throughout the day.

This document and associated material on the World Wide Web (or simply,
the "web") serves as an introduction to this new era in cartography.
The text introduces the basic concepts. Resources on the web, linked directly
from this document, illustrate and expand upon these concepts. The material
is dependent on each other and the reader is encouraged to examine the various
links that are implemented within this document. We begin first with an
overview of the Internet and the World Wide Web.

I. The Internet

The Internet has been described in many ways. In the simplest sense, the
Internet may be thought of as a system for transferring files between computers.
These files, manipulated as numbers and ultimately stored and transferred
in binary 0s and 1s, may consist of text, pictures, graphics, sound, animations,
movies, or even computer programs. Defined in terms of hardware, the Internet
may be thought of as a physical collection of computers, routers, and high-speed
communication lines. In terms of software, it is a network of computer networks
that are based on the TCP/IP protocol. In terms of content, the Internet
is a collection of shared resources. Finally, and most importantly, from
a human standpoint, the Internet is a large and ever-expanding community
of people who contribute to its content and who use its resources.

The beginnings of the Internet can be found in ARPAnet - a computer
network created for the Advanced Research Projects Agency and funded by
the U.S. Department of Defense. The inital purpose of the network was to
help scientists work together and also to create a network with a redundantly
linked structure that would continue to work even after a limited nuclear
attack. The initial Network Control Protocol (NCP) was first implemented
in 1969 between Stanford University, UC-Santa Barbara, and the University
of Utah. ARPANET switched from the NCP protocol to the currently used TCP/IP
(Transmission Control Protocol/ Internet Protocol) on January 1, 1983. Many
view this date as the beginning of the Internet.

The ARPAnet model specified that data communication always occurs between
a source and a destination computer. Further, the network connecting any
two computers is assumed to be unreliable and could disappear at any moment.
Sending data from computer to computer required that it be put in an "envelope,"
called an Internet Protocol (IP) packet, with an appropriate "address."
The computers - not the network - had the responsibility for routing
the messages. All computers could communicate as a peer with any other computer.
If a certain connection between two computers was inoperative, the computer
would re-route the message to another computer that would attempt to "deliver"
the message.

The ARPAnet model was attractive to governments and universities that didn't
have policies concerning the buying of computers from particular vendors.
The model of data communications specified by ARPAnet was emulated on a
local level to connect often different computers within an organization,
particularly when desktop workstations became widely available by the mid-1980s.
Workstations, in particular, created a new model of networking. Rather than
connecting to a single large timesharing computer per site, users wanted
to connect their entire local networks to ARPAnet.

The model was also used in the late 1980s by NSFNET, commissioned by the
National Science Foundation (NSF), an agency of the U.S. government. NSFNET was
designed to distribute the computing power of five supercomputers at major
universities so that they could be used for scholarly research. Increasing
demand on the network throughout the 1980's forced the U.S. government to
commission the NSF to oversee the network. More research and educational
institutions were connected on a high-speed Internet "backbone."
Eventually, Internet service providers expanded the network to include telephone
access from homes.

The Internet has become an international computer network that links academic,
military, government, and commercial computers. It is not managed by any
one entity. Rather, it is a system of networks based on the TCP/IP protocol
that are linked together in a cooporative, non-centralized collaboration.
The Internet consists of five main components or protocols: 1) File Transfer
Protocol (FTP) for exchanging files between computers; 2) Telnet - a remote log-on procedure for accessing programs on remote computers
as though they were local; 3) e-mail - an electronic mail system whereby
one can exchange mail messages between Internet users and many networks
outside the The beginnings of the Internet can be found in ARPAnet -
a computer network created for the Advanced Research Projects Agency and
funded by the U.S. Department of Defense. The inital purpose of the network
was to help scientists work together and also to create a network with a
redundantly linked structure that would continue to work even after a limited
nuclear attack. The initial Network Control Protocol (NCP) was first implemented
in 1969 between Stanford University, UC-Santa Barbara, and the University
of Utah. ARPANET switched from the NCP protocol to the currently used TCP/IP
(Transmission Control Protocol/ Internet Protocol) on January 1, 1983. Many
view this date as the beginning of the Internet.

The ARPAnet model specified that data communication always occurs between
a source and a destination computer. Further, the network connecting any
two computers is assumed to be unreliable and could disappear at any moment.
Sending data from computer to computer required that it be put in an "envelope,"
called an Internet Protocol (IP) packet, with an appropriate "address."
The computers - not the network - had the responsibility for routing
the messages. All computers could communicate as a peer with any other computer.
If a certain connection between two computers was inoperative, the computer
would re-route the message to another computer that would attempt to "deliver"
the message.

The ARPAnet model was attractive to governments and universities that didn't
have policies concerning the buying of computers from particular vendors.
The model of data communications specified by ARPAnet was emulated on a
local level to connect often different computers within an organization,
particularly when desktop workstations became widely available by the mid-1980s.
Workstations, in particular, created a new model of networking. Rather than
connecting to a single large timesharing computer per site, users wanted
to connect their entire local networks to ARPAnet.

The model was also used in the late 1980s by NSFNET, commissioned by the
National Science Foundation (NSF), an agency of the U.S. government. NSFNET was
designed to distribute the computing power of five supercomputers at major
universities so that they could be used for scholarly research. Increasing
demand on the network throughout the 1980's forced the U.S. government to
commission the NSF to oversee the network. More research and educational
institutions were connected on a high-speed Internet "backbone."
Eventually, Internet service providers expanded the network to include telephone
access from homes.

The Internet has become an international computer network that links academic,
military, government, and commercial computers. It is not managed by any
one entity. Rather, it is a system of networks based on the TCP/IP protocol
that are linked together in a cooporative, non-centralized collaboration.
The Internet consists of five main components or protocols: 1) File Transfer
Protocol (FTP) - for exchanging files between computers; 2) Telnet - a remote log-on procedure for accessing programs on remote computers
as though they were local; 3) e-mail - an electronic mail system whereby
one can exchange mail messages between Internet users and many networks
outside the Internet (e.g., BITNET); 4) Newsgroups - discussion groups
which distribute information to groups of users providing a forum for researchers;
and 5) the World Wide Web - a graphical distributed hypermedia system
that incorporates most aspects of the previous four services and delivers
files in multiple forms, including text, pictures, sound, and animation.

The text-based file transfer systems, including FTP, Telnet, e-mail, and
newsgroups developed quickly throughout the 1980's. FTP servers became fairly
widespread by the end of the decade but as the number of available files
kept increasing, searching for a particular file became unmanageable. Searching
systems, including Archie and Gopher, were established to help find particular
files. The complexity of using these systems limited their general usefulness.
The predominance of text files and the difficulty of transferring and viewing
graphic files made the system less than appealing to most computer users.

The World Wide Web

The introduction of the World Wide Web in the early 1990's addressed many
of the usability problems associated with computer networks. Files could
now be accessed using a pointing device such as a mouse. A link within a
document could access another document, on that computer or any other that
supported this protocol. The selection of a link automatically made a connection
to the remote computer and downloaded the document which could be a text,
graphic, sound, animation, or any other type of file. Based on the concepts
of hypertext and hypermedia, the web promoted a logical linking of files,
much as the human brain links related pieces of information. The World Wide
Web is a milestone in network computing technology because it has made it
possible for a person with little computing background to make use of the
Internet. It is largely responsible for the dramatic growth of the Internet
during the early part of the 1990's.

The World Wide Web was conceived at the European Particle Physics Laboratory
(CERN) located near Geneva, Switzerland in 1989. Tim Berners-Lee played
a large role in designing the system. It was intended to assist researchers
in high energy physics research by linking related documents. The developers
wanted to create a seamless network in which information from any source
could be accessed in a simple and consistent way. Before the WWW, accessing
the needed information required the use of many different computer programs
largely due to the incompatibility between different sorts of computers.
The WWW introduced the principle of "universal readership," which
states that networked information should be accessible from any type of
computer in any country with a single program. A prototype of the new protocol
was finished in 1991 and was largely accepted by 1994. The system was quickly
embraced because it also incorporated the previous protocols for file exchange,
including FTP, newsgroups, and mail.

The popularity of the WWW can be measured by the quick adoption of the Mosaic
WWW browser. Developed and freely distributed by the National Center for
Supercomputer Applications (NCSA) in Urbana, Illinois, Mosaic became an
instant success. Released for all common computer platforms, including UNIX,
PC/Windows, and Macintosh, in September of 1993, it was widely used in a
matter of months. Implementing the hypermedia file-access structure, the
program incorporated hypertext and hyperimages, to create links to other
documents, either text or graphic
The growth of the web during this period was particularly dramatic. The
graph in Figure 1.1 illustrates the early increase in WWW packets and bytes
relative to other network traffic such as FTP and Gopher. Much of the increase
in WWW traffic can be attributed to Internet access by Internet access providers
and commercial ventures such as America Online.

World Wide Web Browsers

Mosaic from NCSA was the first, widely-accepted, multimedia-based web browser.
Many other web browsers have since become available. Some browsers, such
as Lynx, only display text. This book is dependent on the working knowledge
of a browser that displays text, graphics, and animation files and plays
sound.

One of the more popular browsers is Netscape Navigator. Its main programmer,
Marc Andreessen, wrote Mosaic and left NCSA to help form Netscape Communications,
Inc. The company experienced phenomenal initial investment in the mid-1990s
based on speculation of continued growth of the Internet, particularly the
web. A variety of other browsers are also available. Updated versions of
Mosaic can still be obtained at no cost from NCSA. Microsoft provides the
Explorer browser along with its Windows operating systems. Updates to the
popular browsers are available through the web and new functions are being
added to the software on a continual basis.
All browsers download and display material from an "http" site
(HyperText Transfer Protocol). The "http" address has a consistent
structure, as indicated below:

http://maps.unomaha.edu

The "http" prefix is always followed by a colon and two slashes.
Following this is the actual address beginning with the name that has been
assigned to a particular computer, in this case, "maps". After
this is the "domain" name that indicates where that computer is
located (the University of Nebraska at Omaha, or "unomaha"). Finally,
the "edu" tells us that the computer is at an educational site.
This particular address will display a "home page" for that computer.
By adding directory and file name information, one can access other files
on the system:

http://maps.unomaha.edu/book2/chapter_1.html

In this case, a file called chapter_1.html within a directory (or folder)
called book2 is displayed. This file contains hypertext links that access
other sites on the web. This particular file is the web page associated
with this chapter.

Browsers also have the option of saving addresses for a particular site
as a "bookmark" so that you do not need to type the address each
time you want to access a file. This is usually implemented as a menu option
and new addresses are added to the menu. The current document is usually
displayed in a "Location:" bar at the top of the window. It is
important to become accustomed to the use of a particular web browser, including
such tasks as typing in the location and saving the location as a bookmark.
Other aspects of the browser program can usually be learned by examining
a help facility built into the program.

Web Search Engines

A search engine is a method of indexing and finding material on the web.
It consists of two basic programs. The first program examines all known
web pages and creates an index based on a defined set of keywords. The second
program responds to user "keyword" requests to this index. A particular
keyword may return a large number of matches. The list of matches are sorted
based on a variety of criteria but is usually a function of how often the
particular keyword is included in the document.
Search engines work continuously. One of the most powerful search engines
on the web is AltaVista, operated by the Digital Equipment Corporation.
Its search engine indexes material - "crawls the web" -
at 3 million pages a day. AltaVista went public in December of 1995. At
the time it had indexed 16 million web pages. Five months later the index
had grown to more than 30 million pages and the site was receiving twelve
million daily keyword requests. The purpose of the search engine is both
find new material and to update HTTP addresses to the pages that have already
been indexed.
There are many different search engines (see the list in the home page associated
with this chapter). Depending on the search engine, a keyword will return
a large number of documents. For example, the keyword "maps" returns
1,127,414 matches in AltaVista (mid-1996). This means that the search engine
found this many documents that contained the word "maps". The
combination of "maps+world" returns only 1000. There are many
ways of limiting the search to a more specific topic but the syntax for
doing so varies between different search engines. Effectively "surfing
the web" requires a good working knowledge of several search engines.

II. Maps on the Web

Graphics, including maps and images taken from satellites, have become a
major component of the web. One of the reasons for this is cost. It is simply
less expensive to place color graphics on the web than it is to print in
color on paper. When the additional costs of shipping and distribution are
factored into the printed product, the cost advantages of distributing maps
and images over the Internet become even more apparent.

The advantage of printing, however, is resolution. A typical high-resolution
printer has a resolution of between 1200-3400 dots per inch (dpi; 472 -
1339 dots per cm). In contrast, a computer monitor can only display about
65-120 dpi (25.6 - 47.2 dots per cm). The computer monitor is also limited
in size, typically only 14" to 21" (35.6 cm - 53.3 cm) in diagonal
measure. Printed maps and photographs can be much larger.

We can look at resolution in different ways. The particular type of resolution
that is being referred to here is "spatial" resolution -
the amount of information or data that can be represented per unit area.
Resolution could also refer to other aspects of the display. We might speak
of a "temporal resolution" that would describe how quickly a graphic
can be displayed. We could also think of resolution in the sense of interactivity
- how easily a user can interact with the graphic to change a particular
view.

To overcome the limitation of "spatial resolution," maps displayed
by computer are typically more dynamic. The maps are frequently updated,
they incorporate some type of interaction, or a series of maps can be viewed
as an animation. The combination of maps and the Internet is a significant
development, not only for improving the distribution of maps but also because
it makes a more interactive form of mapping possible - a form of mapping
that engages the map user to a much greater extent than maps on paper.

The distribution of maps over the Internet is not new. Map files have been
distributed for many years using the FTP protocol. However, these files
needed to be subsequently converted and uncompressed before they could be
displayed. One also needed the appropriate display software. It was a time-consuming
and complex process usually performed on UNIX workstations. WWW browsers
incorporated the conversion and display software, either internally or with
the help of external "viewer" applications. This made the display
of maps possible with a point-and-click interface.

Graphics on the Internet are usually based on a raster format in which the
image is represented as a grid of "picture elements" called pixels.
Each grid square is assigned a color that is represented in the computer
as a number. The most common grid format for graphic files is GIF (Graphics
Interchange Format). Limited to 256 shades or colors, GIF files have become
a standard way of distributing pictures in electronic form. This graphics
format is widely adopted and supported by almost all web browsers. An alternative
image display format is JPEG (Joint Photographic Experts Group). This format
is better suited for pictures because it is not limited to 256 shades or
colors. However, the format makes use of compression algorithms that result
in a loss of detail. Although not noticable on pictures, this loss of sharpness
is apparent on maps through a fuzziness introduced in the line-work.

Many of the static maps available on the Internet have been scanned from
paper maps and stored in a GIF or JPEG format. Examples are this
map of Africa and this
map of Burma. While the scanning of maps represents a quick way to transform
a map into digital form for transmission, the maps are often not legible.
Sometimes, so little care is taken in the scanning process that the text
on the back side of the paper map will be appear in the scanned version.
The screen pattern will be visible on printed maps, particularly those
printed in color.

Other forms of static maps include weather maps, maps of demographic distributions
(World
Per Capita GNP, United
States Per Capita GNP) , and other types of thematic maps. Most of these
maps have been designed specifically for display on a computer terminal
and are much more legible than maps that have been simply scanned. Weather
maps, in particular, account for a great deal of network traffic, and incorporate
map design considerations for display on a computer terminal.

Static maps with a higher spatial resolution are also available on the Web.
A common file type that is used for these maps is Adobe's Portable Document
Format (PDF). These files are stored in a format called Postscript that
is used by most printers. Although viewable on the screen of the computer,
the files are designed for printing. PDF files are "resolution independent"
so they can take advantage of the resolution of the printer. An
example of a map in PDF format.

A variety of web sites incorporate interactive maps. These maps can be changed
by the user by choosing various map display options. Map sites such as those
located at Xerox Parc and
the Fourmi Laboratory
in Switzerland are early examples of the type of interaction that was implemented
with maps on the web. Both sites receive a considerable amount of traffic.
The interactive Parc site allows the display of alternative projections
and separate map layers including country boundaries, waterways, and transportation
networks. The map site at the Fourmi Laboratory displays views of the earth
from the sun, the moon or orbiting satellites, and includes the overlay
of current cloud patterns derived from weather satellites. The XEROX Parc
site is one of the most heavily used map sites. By the mid-1990's it was
responding to nearly 90,000 requests for world maps. Present Xerox
Parc map site usage.

Maps that are updated on a frequent basis include maps of traffic flow,
as in this example of the current traffic
in Houston . Interactive street level mapping of the US is available
from both MapQuest and MapBlast.
These maps are based on the TIGER map file, a product of the U.S. Census
Bureau. The lcoation of bank teller machines on these maps can be obtained
through VISA. Interactive mapping with demographic data is available through CIESIN.
This site lets the user choose an area and a data value to map within the
U.S. An index
of maps on the Internet lists many more sites that distribute maps.

Animated maps are also available through computer networks. Map animations
are usually stored in a format designed for the display of movies, such
as QuickTime or MPEG. The most common examples of animated maps on the Internet
are those of weather patterns, most often depicting the movement of clouds
as seen on television weather forecasts. The movement of cloud patterns
associated with hurricanes is especially suited for viewing as an animation.
Other types of animated maps include terrain fly-throughs in which a landscape,
usually somewhat mountainous, is viewed as if it were being flown through
with an airplane or jet. Animations are also available showing population
growth in a region. Here a shading is applied in a progressive fashion to
depict the pattern of population growth. Finally, animations are available
that depict temporal trends of alternative methods of data classification.
A list of animated maps available through the web is available below:

The Printing Analogy

The first known map dates to about 4500 years ago. However, it wasn't until
500 years ago that humans discovered a way to accurately and quickly duplicate
maps. As late as the 1400's, all maps were still painstakingly reproduced
by hand, so there were very few maps in existence. Beginning in the latter
part of the Renaissance, maps began to be printed in Europe. The development
of printing meant that maps could be easily reproduced while being faithful
to the original. It also meant that more people had the opportunity to see
and use maps.

The impact of printing on mapping has a good analogy in the present transition
to the distribution of maps through computer networks. Like the printing
of maps, computer networks have increased the distribution of maps. Printing
made it possible to produce thousands of identical maps in a short amount
of time. The Internet has made it possible to simultaneously "print"
and distribute thousands of maps every second.

Maps on computer networks are delivered in a fraction of the time required
to distribute maps on paper. A single network request for a map supercedes
the former time-consuming map printing and distribution processes. A process
that is analogous to the printing and shipping of maps is done on the Internet
in a matter of seconds. Like printing, the Internet represents a revolution
for mapping in the sense that it redefines how maps are made and used. As
you have seen, maps on the Internet tend to be interactive - often
allowing the user to change the perspective, the projection, or the level
of detail. They tend also to be more up-to-date. Weather maps, for example,
are posted on a hourly basis. Finally, maps are used differently than before.
They are accessed through a hyperlinking structure that makes it possible
to engage the map user on a higher-level than what is possible with a map
on paper.

The Map Use Problem

One of the major problems associated with maps is that of map use. Many
people have difficulty using maps even within highly educated populations.
It has been estimated that more than half of the educated population do
not have a basic competency with maps. Most people are essentially map illiterate.
The reasons for this are not well understood. Some see the problem related
to a lack of education specific to map use while others say it is the maps
themselves and, more specifically, the medium of paper that is used to display
them. But, the result is clear: people have poorly formed mental representations
of their local environment and especially the space beyond their direct
experience.

The paper medium has been the predominant form of map distribution. However,
the medium does not promote interactivity, a process that many associate
with learning. While some people are able to "make a connection"
with the map on paper and mentally visualize what the map represents, others
have difficulty doing so. Education may help overcome this barrier for some
but it is unlikely that it will make the map on paper a viable form of communication
for a major segment of the population.

One solution to the problem of map use is the interactivity of maps on the
Internet. No longer restricted to the single view offered by maps on paper,
the map user is encouraged to explore alternative methods of representation
- different views that help shape the user's perspective of the world.
The "views" that are presented to people go beyond those offered
by the maps in atlases, either those in paper or electronic forms. The maps
are more current and targeted to specific users. They can also be more interactive
and incorporate animation. The exposure to interactive maps on the Internet
may also lead to better map use skills and both improve and increase the
use of maps on paper.

The Meaning of Maps on the Web

What is the meaning of this change in how maps are delivered to the map
user? Maps are an important source of information from which people form
their impressions about places and distributions. Each map is a view of
the earth that affects the way people think about the world. Our thoughts
about the space in which we live and especially the areas beyond our direct
perception are largely influenced by the representations of space that we
see, and the way we think about our environment influences the way we act
within it. The Internet has already improved the distribution of maps. If
done properly, the Internet also has the potential of improving the quality
of maps as a form of communication, thereby changing both the mental representations
that people have of the world and how people mentally process ideas about
spatial relationships.

The Cost of Map Use

Putting maps in "front of people" is the most important aspect
of map use. The cost of maps are their production and distribution. As noted
earlier in the chapter, the Internet reduces the cost of map distribution,
especially maps in color. Will the decreased cost of map distribution increase
the use of maps? The problem of map distribution is largely one of economics.
Who pays for the making of maps and the costs associated with their distribution?

Mapping is driven by commercial and governmental interests. While business
makes decisions on what to map based on what "will sell," the
decisions of governments are made based on whose interests will be served.
In general, making maps of the country, the world, and other celestial bodies
is considered to be in the "national interest." There is also
a unique interplay between government and commercial mapping. Maps that
are made by governments, often at enormous expense to the taxpayer, are
"repackaged" by the private sector and sold as commercial products.
The cost of these commercial products has been largely subsidized by the
government.

The distribution of maps by the federal government has undergone a huge
transformation as a result of computer networks. As late as the mid-1980's,
most maps were still distributed on paper. Paper maps were sold on a "cost
of distribution" basis - a nominal fee that covered printing,
warehousing and associated expenses. Five years later, computer networks
had become the prodominant form of map distribution by the federal government.
The most remarkable aspect of this transformation is that maps were distributed
at no charge. The free distribution of maps was justified because there
were no printing and warehousing costs associated with maps distributed
through computer networks.

While the maps were now distributed freely, the costs associated with their
use had risen sharply. Computers and computer software were needed to make
the digital maps usable. While it can be argued that with the appropriate
computer software, the digital products were now more useful than the previous
paper product, it cannot be overlooked that fewer people were now in the
position of using the maps that were so distributed. In a very real sense,
the maps that are now distributed by the federal government have become
"maps for the few" - usable only to people with computers,
computer software, a network connection, and the appropriate training.

There is considerable public interest and support of the World Wide Web,
and the Internet in general. Many schools and libraries are establishing
connections to the Internet. The number of people that subscribe to services
such as America Online and Compuserve has increased drastically and the
number of firms that offer Internet access has also expanded. A telling
statistic about changing societal attitudes is that in 1995 consumer computer
sales in the United States surpassed those of televisions. For better or
worse, it seems that our society is becoming "wired" and the form
of information access and delivery is drastically changing. Maps, and geographic
information in general, will be a part of this change.